The myth that obesity is caused by overeating, especially a diet high in fats, is one perpetuated by the sugar industry and the "research" this industry has funded over the decades.

The sugar industry also perpetuated the myths that obesity causes diabetes; that diets high in saturated fats, high cholesterol and overeating generally cause heart disease; and that excess salt causes hypertension (high blood pressure). Anything, in short, to steer attention away from the real cause of these four maladies: sugar.

And the nutrition scientists let it happen. For the past 40 years, people have been deluded into thinking that low-fat diets would reduce obesity and therefore diabetes and heart disease, when all along the enemy was highly refined carbohydrates, especially sugar. They have allowed people to believe that only calories matter and that if you eat more calories than you expend in exercise you will get fat.

Taubes points to the explosion in diabetes, obesity, hypertension, heart disease and cancer that comes with the Western diet and presents the facts and argument that show how everything has been blamed but the real culprit: refined sugar.

Indigenous populations had non-existent rates of the cluster of Western diseases despite many of them having very high-saturated-fat diets; the Inuit, the people on the Tokelau atolls and American Indians are examples.

You will now receive updates fromBreaking News Alert

Breaking News Alert

Then came sugar and Western diseases. They got fat despite many having high-exercise labouring jobs. The people who emigrated from Tokelau to New Zealand and who were closely monitored got Western diseases while those who remained in Tokelau on a high-fat but no-sugar diet of unprocessed pork and coconut did not, at least until their diet changed to one of processed food and high sugar later in the 20th century.

Cancer in the indigenous populations was also almost non-existent, until they took up high-sugar diets. That link is harder to demonstrate, though the role of insulin in feeding cancer cells is becoming clearer.

Taubes points at the way the body metabolises sucrose (a combination of glucose and fructose) and high-fructose cornflour, which are added to almost all processed foods. It results in insulin intolerance, which requires the body to produce more insulin than otherwise, which results in more fat being retained in the cells.

Much research comparing people on supposed links between high-fat diets and obesity and fat build-up revealed no such link, but the nutritionists ignored it.

Sugar is almost certainly addictive; ask any parent dealing with a child's demands for sweets.

British scientist John Yudkin first hypothesised about the danger of sugar in 1957. He wrote the book Pure, White, and Deadly in 1972. But he was derided by sugar-industry-supported American researchers and hounded from academia. The researchers just read the accumulating evidence to suit their existing beliefs.

The sugar industry got the US Federal Drug Administration to ban artificial sweeteners on flimsy evidence that they caused cancer in rats (if you fed enough to them) and set up a big scare campaign against them, even though they were much less harmful than the so-called "natural" sugar they were replacing. Many countries, including Australia, follow FDA recommendations.

Not everyone gets obese, diabetes, heart disease or hypertension on a Western diet, just as not all smokers get lung cancer. There are genetic factors, too, about the way the body metabolises sugar.

But sugar certainly condemns a lot of people to obesity. So we should stop demonising overweight people, and put the blame where it belongs: on those who add sugar to food and the governments who permit it.

Sugar is so easy to consume in bulk. There are seven teaspoons of sugar in a can of Coke. You would need to eat four apples to get that much sugar, but you would also have other stuff to digest so it would be less of a hit. You could easily drink five cans of Coke in a day, and all your other food, but you would be very hard pushed to eat 20 apples and all your other food in a day.

Sugar is almost certainly addictive; ask any parent dealing with a child's demands for sweets.

The evidence against sugar is compelling. Enough for me to try an ALSAP diet (as low sugar as possible). Refined sugar and sugar in processed food is simply unnecessary for good health, rather it is harmful.

However, it would probably be impossible or prohibitively expensive to construct a double-blind randomised trial to prove the point conclusively. It might take years, if not decades, for sugar to do its harm. It might be unethical to feed people high-sugar diets when the evidence against it is so high.

Tobacco was easier. Large populations could be (and were) asked about their smoking habits and monitored for lung cancer. The link was conclusive. Governments (slowly) acted.

They should act on sugar. Food labelling laws in Australia are absurdly lax and uninformative. The typeface is almost unreadable. We should have laws that require larger type with the words "added sugar" and the total sugar percentage of the product. Most people would be astonished at how many product have sugar added and how much sugar is added to them.

Britain and other nations have imposed sugar taxes, but they have been dismissed here.

One more alarming thing. Women with insulin intolerance (and therefore high insulin levels) or metabolic syndrome tend to pass on the disorder through the placenta to their children. Present-day sugar consumption is therefore condemning innocent future generations to Western diseases no matter how little they eat or how much exercise they do.